Filter and export

Publications

What is a Publication?
52 Publications visible to you, out of a total of 52
Peripheral expression of brain-penetrant progranulin rescues pathologies in mouse models of frontotemporal lobar degeneration.

Abstract (Expand)

Progranulin (PGRN) haploinsufficiency is a major risk factor for frontotemporal lobar degeneration with TAR DNA-binding protein 43 (TDP-43) pathology (FTLD-<i>GRN</i>). Multiple therapeutic … strategies are in clinical development to restore PGRN in the CNS, including gene therapy. However, a limitation of current gene therapy approaches aimed to alleviate FTLD-associated pathologies may be their inefficient brain exposure and biodistribution. We therefore developed an adeno-associated virus (AAV) targeting the liver (L) to achieve sustained peripheral expression of a transferrin receptor (TfR) binding, brain-penetrant (b) PGRN variant [AAV(L):bPGRN] in two mouse models of FTLD-<i>GRN</i>, namely, <i>Grn</i> knockout and <i>GrnxTmem106b</i> double knockout mice. This therapeutic strategy avoids potential safety and biodistribution issues of CNS-administered AAVs and maintains sustained concentrations of PGRN in the brain after a single dose. AAV(L):bPGRN treatment reduced several FTLD-<i>GRN</i>-associated pathologies including severe motor function deficits, aberrant TDP-43 phosphorylation, dysfunctional protein degradation, lipid metabolism, gliosis, and neurodegeneration in the brain. The potential translatability of our findings was tested in an in vitro model using cocultured human induced pluripotent stem cell (hiPSC)-derived microglia lacking PGRN and TMEM106B and wild-type hiPSC-derived neurons. As in mice, aberrant TDP-43, lysosomal dysfunction, and neuronal loss were ameliorated after treatment with exogenous TfR-binding protein transport vehicle fused to PGRN (PTV:PGRN). Together, our studies suggest that peripherally administered brain-penetrant PGRN replacement strategies ameliorate FTLD-<i>GRN</i> relevant phenotypes including TDP-43 pathology, neurodegeneration, and behavioral deficits. Our data provide preclinical proof of concept for the use of this AAV platform for treatment of FTLD-<i>GRN</i> and potentially other CNS disorders.

Authors: Marvin Reich, Matthew J Simon, Beate Polke, Iñaki Paris, Georg Werner, Christian Schrader, Lena Spieth, Sonnet S Davis, Sophie Robinson, Gabrielly Lunkes de Melo, Lennart Schlaphoff, Katrin Buschmann, Stefan Berghoff, Todd Logan, Brigitte Nuscher, Lis de Weerd, Dieter Edbauer, Mikael Simons, Jung H Suh, Thomas Sandmann, Mihalis S Kariolis, Sarah L DeVos, Joseph W Lewcock, Dominik Paquet, Anja Capell, Gilbert Di Paolo, Christian Haass

Date Published: 5th Jun 2024

Publication Type: Journal

Cellular depletion of major cathepsin proteases reveals their concerted activities for lysosomal proteolysis.

Abstract (Expand)

Proteins delivered by endocytosis or autophagy to lysosomes are degraded by exo- and endoproteases. In humans 15 lysosomal cathepsins (CTS) act as important physiological regulators. The cysteine … proteases CTSB and CTSL and the aspartic protease CTSD are the most abundant and functional important lysosomal proteinases. Whereas their general functions in proteolysis in the lysosome, their individual substrate, cleavage specificity, and their possible sequential action on substrate proteins have been previously studied, their functional redundancy is still poorly understood. To address a possible common role of highly expressed and functional important CTS proteases, we generated CTSB-, CTSD-, CTSL-, and CTSBDL-triple deficient (KO) human neuroblastoma-derived SH-SY5Y cells and CTSB-, CTSD-, CTSL-, CTSZ and CTSBDLZ-quadruple deficient (KO) HeLa cells. These cells with a combined cathepsin deficiency exhibited enlarged lysosomes and accumulated lipofuscin-like storage material. The lack of the three (SH-SY5Y) or four (HeLa) major CTSs caused an impaired autophagic flux and reduced degradation of endocytosed albumin. Proteome analyses of parental and CTS-depleted cells revealed an enrichment of cleaved peptides, lysosome/autophagy-associated proteins, and potentially endocytosed membrane proteins like the amyloid precursor protein (APP), which can be subject to endocytic degradation. Amino- and carboxyterminal APP fragments accumulated in the multiple CTS-deficient cells, suggesting that multiple CTS-mediated cleavage events regularly process APP. In summary, our analyses support the idea that different lysosomal cathepsins act in concert, have at least partially and functionally redundant substrates, regulate protein degradation in autophagy, and control cellular proteostasis, as exemplified by their involvement in the degradation of APP fragments.

Authors: Lisa Gallwitz, Florian Bleibaum, Matthias Voss, Michaela Schweizer, Katharina Spengler, Dominic Winter, Frederic Zöphel, Stephan Müller, Stefan Lichtenthaler, Markus Damme, Paul Saftig

Date Published: 22nd May 2024

Publication Type: Journal

Lysosomal damage sensing and lysophagy initiation by SPG20-ITCH.

Abstract (Expand)

Cells respond to lysosomal membrane permeabilization by membrane repair or selective macroautophagy of damaged lysosomes, termed lysophagy, but it is not fully understood how this decision is made. … Here, we uncover a pathway in human cells that detects lipid bilayer perturbations in the limiting membrane of compromised lysosomes, which fail to be repaired, and then initiates ubiquitin-triggered lysophagy. We find that SPG20 binds the repair factor IST1 on damaged lysosomes and, importantly, integrates that with the detection of damage-associated lipid-packing defects of the lysosomal membrane. Detection occurs via sensory amphipathic helices in SPG20 before rupture of the membrane. If lipid-packing defects are extensive, such as during lipid peroxidation, SPG20 recruits and activates ITCH, which marks the damaged lysosome with lysine-63-linked ubiquitin chains to initiate lysophagy and thus triages the lysosome for destruction. With SPG20 being linked to neurodegeneration, these findings highlight the relevance of a coordinated lysosomal damage response for cellular homeostasis.

Authors: Pinki Gahlot, Bojana Kravic, Giulia Rota, Johannes van den Boom, Sophie Levantovsky, Nina Schulze, Elena Maspero, Simona Polo, Christian Behrends, Hemmo Meyer

Date Published: 18th Apr 2024

Publication Type: Journal

Shared inflammatory glial cell signature after stab wound injury, revealed by spatial, temporal, and cell-type-specific profiling of the murine cerebral cortex.

Abstract (Expand)

Traumatic brain injury leads to a highly orchestrated immune- and glial cell response partially responsible for long-lasting disability and the development of secondary neurodegenerative diseases. A … holistic understanding of the mechanisms controlling the responses of specific cell types and their crosstalk is required to develop an efficient strategy for better regeneration. Here, we combine spatial and single-cell transcriptomics to chart the transcriptomic signature of the injured male murine cerebral cortex, and identify specific states of different glial cells contributing to this signature. Interestingly, distinct glial cells share a large fraction of injury-regulated genes, including inflammatory programs downstream of the innate immune-associated pathways Cxcr3 and Tlr1/2. Systemic manipulation of these pathways decreases the reactivity state of glial cells associated with poor regeneration. The functional relevance of the discovered shared signature of glial cells highlights the importance of our resource enabling comprehensive analysis of early events after brain injury.

Authors: Christina Koupourtidou, Veronika Schwarz, Hananeh Aliee, Simon Frerich, Judith Fischer-Sternjak, Riccardo Bocchi, Tatiana Simon-Ebert, Xianshu Bai, Swetlana Sirko, Frank Kirchhoff, Martin Dichgans, Magdalena Götz, Fabian J Theis, Jovica Ninkovic

Date Published: 3rd Apr 2024

Publication Type: Journal

Injury-specific factors in the cerebrospinal fluid regulate astrocyte plasticity in the human brain.

Abstract (Expand)

The glial environment influences neurological disease progression, yet much of our knowledge still relies on preclinical animal studies, especially regarding astrocyte heterogeneity. In murine models … of traumatic brain injury, beneficial functions of proliferating reactive astrocytes on disease outcome have been unraveled, but little is known regarding if and when they are present in human brain pathology. Here we examined a broad spectrum of pathologies with and without intracerebral hemorrhage and found a striking correlation between lesions involving blood-brain barrier rupture and astrocyte proliferation that was further corroborated in an assay probing for neural stem cell potential. Most importantly, proteomic analysis unraveled a crucial signaling pathway regulating this astrocyte plasticity with GALECTIN3 as a novel marker for proliferating astrocytes and the GALECTIN3-binding protein LGALS3BP as a functional hub mediating astrocyte proliferation and neurosphere formation. Taken together, this work identifies a therapeutically relevant astrocyte response and their molecular regulators in different pathologies affecting the human cerebral cortex.

Authors: Swetlana Sirko, Christian Schichor, Patrizia Della Vecchia, Fabian Metzger, Giovanna Sonsalla, Tatiana Simon, Martina Bürkle, Sofia Kalpazidou, Jovica Ninkovic, Giacomo Masserdotti, Jean-Frederic Sauniere, Valentina Iacobelli, Stefano Iacobelli, Claire Delbridge, Stefanie M Hauck, Jörg-Christian Tonn, Magdalena Götz

Date Published: 8th Dec 2023

Publication Type: Journal

High-calorie diets uncouple hypothalamic oxytocin neurons from a gut-to-brain satiation pathway via κ-opioid signaling.

Abstract (Expand)

Oxytocin-expressing paraventricular hypothalamic neurons (PVN<sup>OT</sup> neurons) integrate afferent signals from the gut, including cholecystokinin (CCK), to adjust whole-body energy … homeostasis. However, the molecular underpinnings by which PVN<sup>OT</sup> neurons orchestrate gut-to-brain feeding control remain unclear. Here, we show that mice undergoing selective ablation of PVN<sup>OT</sup> neurons fail to reduce food intake in response to CCK and develop hyperphagic obesity on a chow diet. Notably, exposing wild-type mice to a high-fat/high-sugar (HFHS) diet recapitulates this insensitivity toward CCK, which is linked to diet-induced transcriptional and electrophysiological aberrations specifically in PVN<sup>OT</sup> neurons. Restoring OT pathways in diet-induced obese (DIO) mice via chemogenetics or polypharmacology sufficiently re-establishes CCK's anorexigenic effects. Last, by single-cell profiling, we identify a specialized PVN<sup>OT</sup> neuronal subpopulation with increased κ-opioid signaling under an HFHS diet, which restrains their CCK-evoked activation. In sum, we document a (patho)mechanism by which PVN<sup>OT</sup> signaling uncouples a gut-brain satiation pathway under obesogenic conditions.

Authors: Tim Gruber, Franziska Lechner, Cahuê Murat, Raian E Contreras, Eva Sanchez-Quant, Viktorian Miok, Konstantinos Makris, Ophélia Le Thuc, Ismael González-García, Elena García-Clave, Ferdinand Althammer, Quirin Krabichler, Lisa M DeCamp, Russell G Jones, Dominik Lutter, Rhiannan H Williams, Paul T Pfluger, Timo D Müller, Stephen C Woods, John Andrew Pospisilik, Celia P Martinez-Jimenez, Matthias H Tschöp, Valery Grinevich, Cristina Garcia-Caceres

Date Published: 31st Oct 2023

Publication Type: Journal

Distinct molecular profiles of skull bone marrow in health and neurological disorders.

Abstract (Expand)

The bone marrow in the skull is important for shaping immune responses in the brain and meninges, but its molecular makeup among bones and relevance in human diseases remain unclear. Here, we show that … the mouse skull has the most distinct transcriptomic profile compared with other bones in states of health and injury, characterized by a late-stage neutrophil phenotype. In humans, proteome analysis reveals that the skull marrow is the most distinct, with differentially expressed neutrophil-related pathways and a unique synaptic protein signature. 3D imaging demonstrates the structural and cellular details of human skull-meninges connections (SMCs) compared with veins. Last, using translocator protein positron emission tomography (TSPO-PET) imaging, we show that the skull bone marrow reflects inflammatory brain responses with a disease-specific spatial distribution in patients with various neurological disorders. The unique molecular profile and anatomical and functional connections of the skull show its potential as a site for diagnosing, monitoring, and treating brain diseases.

Authors: Zeynep Ilgin Kolabas, Louis B Kuemmerle, Robert Perneczky, Benjamin Förstera, Selin Ulukaya, Mayar Ali, Saketh Kapoor, Laura M Bartos, Maren Büttner, Ozum Sehnaz Caliskan, Zhouyi Rong, Hongcheng Mai, Luciano Höher, Denise Jeridi, Muge Molbay, Igor Khalin, Ioannis K Deligiannis, Moritz Negwer, Kenny Roberts, Alba Simats, Olga Carofiglio, Mihail I Todorov, Izabela Horvath, Furkan Ozturk, Selina Hummel, Gloria Biechele, Artem Zatcepin, Marcus Unterrainer, Johannes Gnörich, Jay Roodselaar, Joshua Shrouder, Pardis Khosravani, Benjamin Tast, Lisa Richter, Laura Díaz-Marugán, Doris Kaltenecker, Laurin Lux, Ying Chen, Shan Zhao, Boris-Stephan Rauchmann, Michael Sterr, Ines Kunze, Karen Stanic, Vanessa W Y Kan, Simon Besson-Girard, Sabrina Katzdobler, Carla Palleis, Julia Schädler, Johannes C Paetzold, Sabine Liebscher, Anja E Hauser, Özgün Gökçe, Heiko Lickert, Hanno Steinke, Corinne Benakis, Christian Braun, Celia P Martinez-Jimenez, Katharina Buerger, Nathalie L Albert, Günter Höglinger, Johannes Levin, Christian Haass, Anna Kopczak, Martin Dichgans, Joachim Havla, Tania Kümpfel, Martin Kerschensteiner, Martina Schifferer, Mikael Simons, Arthur Liesz, Natalie Krahmer, Omer A Bayraktar, Nicolai Franzmeier, Nikolaus Plesnila, Suheda Erener, Victor G Puelles, Claire Delbridge, Harsharan Singh Bhatia, Farida Hellal, Markus Elsner, Ingo Bechmann, Benjamin Ondruschka, Matthias Brendel, Fabian J Theis, Ali Ertürk

Date Published: 17th Aug 2023

Publication Type: Journal

Powered by
 (v.1.15.0)
About FAIRDOM | About SyNergy (Munich Cluster for Systems Neurology) | Funding and Programmes | Credits
Copyright © 2008 - 2024 The University of Manchester and HITS gGmbH